Fan assembly for a packaged terminal air conditioner unit

ABSTRACT

A packaged terminal air conditioner unit (PTAC) includes a vent aperture defined in a bulkhead of the PTAC and a fan assembly for urging a flow of make-up air through the vent aperture. The fan assembly includes a fan duct fluidly coupled to the bulkhead over the vent aperture, the fan duct defining an inlet that extends away from the bulkhead toward a rear of the PTAC. An auxiliary fan is mounted to the fan duct for urging the flow of make-up air through the vent aperture, the auxiliary fan including a plurality of fan blades and a stabilizer ring extending about the circumferential direction between the plurality of fan blades.

FIELD OF THE INVENTION

The present disclosure relates generally to air conditioner units, andmore particularly to fan assemblies for providing make-up air topackaged terminal air conditioner units.

BACKGROUND OF THE INVENTION

Air conditioner or conditioning units are conventionally utilized toadjust the temperature indoors—i.e. within structures such as dwellingsand office buildings. Such units commonly include a closed refrigerationloop to heat or cool the indoor air. Typically, the indoor air isrecirculated while being heated or cooled. A variety of sizes andconfigurations are available for such air conditioner units. Forexample, some units may have one portion installed within the indoorsthat is connected, by e.g., tubing carrying the refrigerant, to anotherportion located outdoors. These types of units are typically used forconditioning the air in larger spaces.

Another type of unit, sometimes referred to as a packaged terminal airconditioner unit (PTAC), may be used for somewhat smaller indoor spacesthat are to be air conditioned. These units may include both an indoorportion and an outdoor portion separated by a bulkhead and may beinstalled in windows or positioned within an opening of an exterior wallof a building. PTACs often need to draw air from the outdoor portioninto the indoor portion. Accordingly, certain PTACs allow for theintroduction of make-up air into the indoor space, e.g., through a ventaperture defined in the bulkhead that separates the indoor and outdoorside of the unit.

Conventional PTACs may further include an auxiliary fan and/or make-upair module fluidly coupled with the vent aperture to urge a flow ofmake-up air from the outdoor side of the PTAC into the conditioned room.However, positioning the auxiliary fan within the vent aperture orproximate to bulkhead results in the auxiliary fan competing with theoutdoor fan. In this regard, for example, the outdoor fan may generate anegative pressure that actually draws air through vent aperture from theindoor portion.

Certain conventional PTACs include fan ducts for housing the auxiliaryfan. However, due to manufacturing limitations, such fan ducts are oftenlimited to straight ducts extending between two points, and such ductshave a tendency to permit the propagation of noise from outdoor toindoor. Moreover, conventional auxiliary fans are loud and generateblade “growl” or fluttering, particularly during transient operationwhen the fan is throttling up or down. For example, the sparseness ofblades and low twist camber do little to reflect outside to inside noisetransmissions. Increased noise can be a nuisance to occupants of theconditioned room or otherwise result in a less desirable consumerexperience. Therefore, sound penetration into the room is preferablyminimized.

Accordingly, improved air conditioner units and make-up air modules forproviding make-up air would be useful. More specifically, a packagedterminal air conditioner unit that can supply the requested make-up airwhile reducing auxiliary fan noise would be particularly beneficial.

BRIEF DESCRIPTION OF THE INVENTION

The present subject matter provides a packaged terminal air conditionerunit (PTAC) including a vent aperture defined in a bulkhead of the PTACand a fan assembly for urging a flow of make-up air through the ventaperture. The fan assembly includes a fan duct fluidly coupled to thebulkhead over the vent aperture, the fan duct defining an inlet thatextends away from the bulkhead toward a rear of the PTAC. An auxiliaryfan is mounted to the fan duct for urging the flow of make-up airthrough the vent aperture, the auxiliary fan including a plurality offan blades and a stabilizer ring extending about the circumferentialdirection between the plurality of fan blades. Additional aspects andadvantages of the invention will be set forth in part in the followingdescription, may be obvious from the description, or may be learnedthrough practice of the invention.

In accordance with one embodiment, a packaged terminal air conditionerunit defining a vertical, a lateral, and a transverse direction isprovided. The packaged terminal air conditioner unit includes a bulkheaddefining an indoor portion and an outdoor portion separated along thetransverse direction and a vent aperture defined in the bulkhead. A fanduct defines a flow passage having an inlet and an outlet, the outlet ofthe fan duct being attached to the bulkhead to fluidly couple the flowpassage to the vent aperture, and the inlet extends away from thebulkhead toward a rear of the packaged terminal air conditioner unit.

In accordance with another embodiment, a fan assembly for a packagedterminal air conditioner unit is provided. The packaged terminal airconditioner unit defines a vertical, a lateral, and a transversedirection, and includes a bulkhead defining a vent aperture. The fanassembly includes a fan duct defining a flow passage having an inlet andan outlet, the outlet of the fan duct being attached to the bulkhead tofluidly couple the flow passage to the vent aperture, and the inletextending away from the bulkhead toward a rear of the packaged terminalair conditioner unit. An auxiliary fan is mounted to the fan duct and isconfigured for urging a flow of make-up air through the vent aperture.The auxiliary fan defines an axial, a radial, and a circumferentialdirection and includes a plurality of fan blades, each fan bladeextending between a root and a tip. A stabilizer ring extends about thecircumferential direction between the plurality of fan blades.

These and other features, aspects and advantages of the presentinvention will become better understood with reference to the followingdescription and appended claims. The accompanying drawings, which areincorporated in and constitute a part of this specification, illustrateembodiments of the invention and, together with the description, serveto explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including thebest mode thereof, directed to one of ordinary skill in the art, is setforth in the specification, which makes reference to the appendedfigures.

FIG. 1 provides a perspective view of an air conditioner unit, with partof an indoor portion exploded from a remainder of the air conditionerunit for illustrative purposes, in accordance with one exemplaryembodiment of the present disclosure.

FIG. 2 is another perspective view of components of the indoor portionof the exemplary air conditioner unit of FIG. 1.

FIG. 3 is a schematic view of a refrigeration loop in accordance withone embodiment of the present disclosure.

FIG. 4 is a rear perspective view of an outdoor portion of the exemplaryair conditioner unit of FIG. 1, illustrating a vent aperture in abulkhead in accordance with one embodiment of the present disclosure.

FIG. 5 is a front perspective view of the exemplary bulkhead of FIG. 4with a vent door illustrated in the open position in accordance with oneembodiment of the present disclosure.

FIG. 6 is a rear perspective view of the exemplary air conditioner unitand bulkhead of FIG. 4 including a fan assembly for providing make-upair in accordance with one embodiment of the present disclosure.

FIG. 7 is a top view of components of the exemplary air conditioner unitof FIG. 1 according to an exemplary embodiment of the present subjectmatter.

FIG. 8 depicts close-up perspective view of the exemplary fan assemblyof FIG. 6 according to example embodiments of the present subjectmatter.

FIG. 9 provides a top, cross sectional view of the exemplary airconditioner unit of FIG. 1 and the exemplary fan assembly of FIG. 6.

FIG. 10 provides a rear view of the exemplary air conditioner unit ofFIG. 1 and the exemplary fan assembly of FIG. 6 with an auxiliary fanillustrated in phantom.

FIG. 11 provides a perspective view of a fan duct of the exemplary fanassembly of FIG. 6 according to an exemplary embodiment of the presentsubject matter.

FIG. 12 provides an exploded view of the exemplary fan duct of FIG. 11.

FIG. 13 provides a partially exploded view of the exemplary fan assemblyof FIG. 6.

FIG. 14 provides a perspective view of an auxiliary fan that may be usedwith the exemplary fan assembly of FIG. 6.

FIG. 15 provides an exploded view of an electronics assembly of theexemplary fan assembly of FIG. 6.

FIG. 16 provides a front perspective view of an electronics enclosure ofthe exemplary electronics assembly of FIG. 15.

FIG. 17 provides a rear perspective view of the exemplary electronicsenclosure of FIG. 16.

Repeat use of reference characters in the present specification anddrawings is intended to represent the same or analogous features orelements of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference now will be made in detail to embodiments of the invention,one or more examples of which are illustrated in the drawings. Eachexample is provided by way of explanation of the invention, notlimitation of the invention. In fact, it will be apparent to thoseskilled in the art that various modifications and variations can be madein the present invention without departing from the scope or spirit ofthe invention. For instance, features illustrated or described as partof one embodiment can be used with another embodiment to yield a stillfurther embodiment. Thus, it is intended that the present inventioncovers such modifications and variations as come within the scope of theappended claims and their equivalents.

Referring now to FIGS. 1 and 2, an air conditioner unit 10 is provided.The air conditioner unit 10 is a one-unit type air conditioner, alsoconventionally referred to as a room air conditioner or a packagedterminal air conditioner (PTAC). The unit 10 includes an indoor portion12 and an outdoor portion 14, and generally defines a vertical directionV, a lateral direction L, and a transverse direction T. Each directionV, L, T is perpendicular to each other, such that an orthogonalcoordinate system is generally defined.

A housing 20 of the unit 10 may contain various other components of theunit 10. Housing 20 may include, for example, a rear grill 22 and a roomfront 24 which may be spaced apart along the transverse direction T by awall sleeve 26. The rear grill 22 may be part of the outdoor portion 14,and the room front 24 may be part of the indoor portion 12. Componentsof the outdoor portion 14, such as an outdoor heat exchanger 30, anoutdoor fan 32, and a compressor 34 may be housed within the wall sleeve26. A fan shroud 36 may additionally enclose outdoor fan 32, as shown.

Indoor portion 12 may include, for example, an indoor heat exchanger 40,a blower fan or indoor fan 42, and a heating unit 44. These componentsmay, for example, be housed behind the room front 24. Additionally, abulkhead 46 may generally support and/or house various other componentsor portions thereof of the indoor portion 12, such as indoor fan 42 andthe heating unit 44. Bulkhead 46 may generally separate and define theindoor portion 12 and outdoor portion 14.

Outdoor and indoor heat exchangers 30, 40 may be components of arefrigeration loop 48, which is shown schematically in FIG. 3.Refrigeration loop 48 may, for example, further include compressor 34and an expansion device 50. As illustrated, compressor 34 and expansiondevice 50 may be in fluid communication with outdoor heat exchanger 30and indoor heat exchanger 40 to flow refrigerant therethrough as isgenerally understood. More particularly, refrigeration loop 48 mayinclude various lines for flowing refrigerant between the variouscomponents of refrigeration loop 48, thus providing the fluidcommunication there between. Refrigerant may thus flow through suchlines from indoor heat exchanger 40 to compressor 34, from compressor 34to outdoor heat exchanger 30, from outdoor heat exchanger 30 toexpansion device 50, and from expansion device 50 to indoor heatexchanger 40. The refrigerant may generally undergo phase changesassociated with a refrigeration cycle as it flows to and through thesevarious components, as is generally understood. Suitable refrigerantsfor use in refrigeration loop 48 may include pentafluoroethane,difluoromethane, or a mixture such as R410a, although it should beunderstood that the present disclosure is not limited to such exampleand rather that any suitable refrigerant may be utilized.

As is understood in the art, refrigeration loop 48 may be alternately beoperated as a refrigeration assembly (and thus perform a refrigerationcycle) or a heat pump (and thus perform a heat pump cycle). As shown inFIG. 3, when refrigeration loop 48 is operating in a cooling mode andthus performs a refrigeration cycle, the indoor heat exchanger 40 actsas an evaporator and the outdoor heat exchanger 30 acts as a condenser.Alternatively, when the assembly is operating in a heating mode and thusperforms a heat pump cycle, the indoor heat exchanger 40 acts as acondenser and the outdoor heat exchanger 30 acts as an evaporator. Theoutdoor and indoor heat exchangers 30, 40 may each include coils throughwhich a refrigerant may flow for heat exchange purposes, as is generallyunderstood.

According to an example embodiment, compressor 34 may be a variablespeed compressor. In this regard, compressor 34 may be operated atvarious speeds depending on the current air conditioning needs of theroom and the demand from refrigeration loop 48. For example, accordingto an exemplary embodiment, compressor 34 may be configured to operateat any speed between a minimum speed, e.g., 1500 revolutions per minute(RPM), to a maximum rated speed, e.g., 3500 RPM. Notably, use ofvariable speed compressor 34 enables efficient operation ofrefrigeration loop 48 (and thus air conditioner unit 10), minimizesunnecessary noise when compressor 34 does not need to operate at fullspeed, and ensures a comfortable environment within the room.

In exemplary embodiments as illustrated, expansion device 50 may bedisposed in the outdoor portion 14 between the indoor heat exchanger 40and the outdoor heat exchanger 30. According to the exemplaryembodiment, expansion device 50 may be an electronic expansion valvethat enables controlled expansion of refrigerant, as is known in theart. More specifically, electronic expansion device 50 may be configuredto precisely control the expansion of the refrigerant to maintain, forexample, a desired temperature differential of the refrigerant acrossthe indoor heat exchanger 40. In other words, electronic expansiondevice 50 throttles the flow of refrigerant based on the reaction of thetemperature differential across indoor heat exchanger 40 or the amountof superheat temperature differential, thereby ensuring that therefrigerant is in the gaseous state entering compressor 34. According toalternative embodiments, expansion device 50 may be a capillary tube oranother suitable expansion device configured for use in a thermodynamiccycle.

According to the illustrated exemplary embodiment, outdoor fan 32 is anaxial fan and indoor fan 42 is a centrifugal fan. However, it should beappreciated that according to alternative embodiments, outdoor fan 32and indoor fan 42 may be any suitable fan type. In addition, accordingto an exemplary embodiment, outdoor fan 32 and indoor fan 42 arevariable speed fans. For example, outdoor fan 32 and indoor fan 42 mayrotate at different rotational speeds, thereby generating different airflow rates. It may be desirable to operate fans 32, 42 at less thantheir maximum rated speed to ensure safe and proper operation ofrefrigeration loop 48 at less than its maximum rated speed, e.g., toreduce noise when full speed operation is not needed. In addition,according to alternative embodiments, fans 32, 42 may be operated tourge make-up air into the room.

According to the illustrated embodiment, indoor fan 42 may operate as anevaporator fan in refrigeration loop 48 to encourage the flow of airthrough indoor heat exchanger 40. Accordingly, indoor fan 42 may bepositioned downstream of indoor heat exchanger 40 along the flowdirection of indoor air and downstream of heating unit 44.Alternatively, indoor fan 42 may be positioned upstream of indoor heatexchanger 40 along the flow direction of indoor air, and may operate topush air through indoor heat exchanger 40.

Heating unit 44 in exemplary embodiments includes one or more heaterbanks 60. Each heater bank 60 may be operated as desired to produceheat. In some embodiments as shown, three heater banks 60 may beutilized. Alternatively, however, any suitable number of heater banks 60may be utilized. Each heater bank 60 may further include at least oneheater coil or coil pass 62, such as in exemplary embodiments two heatercoils or coil passes 62. Alternatively, other suitable heating elementsmay be utilized.

The operation of air conditioner unit 10 including compressor 34 (andthus refrigeration loop 48 generally) indoor fan 42, outdoor fan 32,heating unit 44, expansion device 50, and other components ofrefrigeration loop 48 may be controlled by a processing device such as acontroller 64. Controller 64 may be in communication (via for example asuitable wired or wireless connection) to such components of the airconditioner unit 10. Controller 64 may include a memory and one or moreprocessing devices such as microprocessors, CPUs or the like, such asgeneral or special purpose microprocessors operable to executeprogramming instructions or micro-control code associated with operationof unit 10. The memory may represent random access memory such as DRAM,or read only memory such as ROM or FLASH. In one embodiment, theprocessor executes programming instructions stored in memory. The memorymay be a separate component from the processor or may be includedonboard within the processor.

Unit 10 may additionally include a control panel 66 and one or more userinputs 68, which may be included in control panel 66. The user inputs 68may be in communication with the controller 64. A user of the unit 10may interact with the user inputs 68 to operate the unit 10, and usercommands may be transmitted between the user inputs 68 and controller 64to facilitate operation of the unit 10 based on such user commands. Adisplay 70 may additionally be provided in the control panel 66, and maybe in communication with the controller 64. Display 70 may, for examplebe a touchscreen or other text-readable display screen, or alternativelymay simply be a light that can be activated and deactivated as requiredto provide an indication of, for example, an event or setting for theunit 10.

Referring briefly to FIG. 4, a vent aperture 80 may be defined inbulkhead 46 providing fluid communication between indoor portion 12 andoutdoor portion 14. Vent aperture 80 may be utilized in an installed airconditioner unit 10 to allow outdoor air to flow into the room throughthe indoor portion 12. In this regard, in some cases it may be desirableto allow outside air (i.e., “make-up air”) to flow into the room inorder, e.g., to meet government regulations, to compensate for negativepressure created within the room, etc. In this manner, according to anexemplary embodiment, make-up air may be provided into the room throughvent aperture 80 when desired.

As shown in FIG. 5, a vent door 82 may be pivotally mounted to thebulkhead 46 proximate to vent aperture 80 to open and close ventaperture 80. More specifically, as illustrated, vent door 82 ispivotally mounted to the indoor facing surface of indoor portion 12.Vent door 82 may be configured to pivot between a first, closed positionwhere vent door 82 prevents air from flowing between outdoor portion 14and indoor portion 12, and a second, open position where vent door 82 isin an open position (as shown in FIG. 5) and allows make-up air to flowinto the room. According to the illustrated embodiment vent door 82 maybe pivoted between the open and closed position by an electric motor 84controlled by controller 64, or by any other suitable method.

In some cases, it may be desirable to treat or condition make-up airflowing through vent aperture 80 prior to blowing it into the room. Forexample, outdoor air which has a relatively high humidity level mayrequire treating before passing into the room. In addition, if theoutdoor air is cool, it may be desirable to heat the air before blowingit into the room. Therefore, according to an exemplary embodiment of thepresent subject matter, unit 10 may further include an auxiliary sealedsystem that is positioned over vent aperture 80 for conditioning make-upair. The auxiliary sealed system may be a miniature sealed system thatacts similar to refrigeration loop 48, but conditions only the airflowing through vent aperture 80. According to alternative embodiments,such as that described herein, make-up air may be urged through ventaperture 80 without the assistance of an auxiliary sealed system.Instead, make-up air is urged through vent aperture 80 may beconditioned at least in part by refrigeration loop 48, e.g., by passingthrough indoor heat exchanger 40. Additionally, the make-up air may beconditioned immediately upon entrance through vent aperture 80 orsequentially after combining with the air stream induced through indoorheat exchanger 40.

Referring now to FIGS. 6 through 10, a fan assembly 100 will bedescribed according to an exemplary embodiment of the present subjectmatter. According to the illustrated embodiment, fan assembly 100 isgenerally configured for urging the flow of makeup air through ventaperture 80 and into a conditioned room without the assistance of anauxiliary sealed system. However, should be appreciated that fanassembly 100 is described herein for the purpose of explaining aspectsof the present subject, and that variations and modifications may bemade to fan assembly 100 while remaining within scope of the presentsubject matter. In this regard, fan assembly 100 could be used inconjunction with a make-up air module including an auxiliary sealedsystem for conditioning the flow of make-up air.

As illustrated, fan assembly 100 includes a fan duct 102 that defines aflow passage 104 that is in fluid communication with vent aperture 80.In this manner, the flow of makeup air may pass through flow passage 104and vent aperture 80 into the conditioned room or indoor portion 12.More specifically, fan duct 102 may define an inlet 106 and an outlet108 spaced apart from each other along the transverse direction T.Outlet 108 of fan duct 102 is attached to bulkhead 46 of air conditionerunit 10 to fluidly couple flow passage 104 to vent aperture 80. As willbe described in detail below, inlet 106 of fan duct 102 extends awayfrom bulkhead 46 toward rear grill 22 of air conditioner unit 10.

According to the illustrated embodiment, an auxiliary fan 120 is mountedto fan duct 102 and is generally configured for urging a flow of makeupair (as indicated by arrows labeled with reference numeral 122 in FIG.7) from outdoor portion 14 through flow passage 104 and vent aperture 80to indoor portion 12. According to the illustrated embodiment, auxiliaryfan 120 is an axial fan. For example, one exemplary axial fan that maybe used with fan assembly will be described below in reference to FIG.14. However, it should be appreciated that any other suitable number,type, and configuration of fan or blower could be used to urge a flow ofmakeup air according to alternative embodiments.

As illustrated, auxiliary fan 120 is positioned at inlet 106 of fan duct102, e.g., remote from outlet 108. In addition, fan assembly 100(including fan duct 102 and auxiliary fan 120) is illustrated as beingpositioned within outdoor portion 14 of air conditioner unit 10.However, it should be appreciated that fan assembly 100 may bepositioned in any other suitable location within air conditioner unit 10and auxiliary fan 120 may be positioned at any other suitable locationwithin or in fluid communication with fan duct 102. The embodimentsdescribed herein are only exemplary and are not intended to limit thescope present subject matter.

As best shown in FIG. 7, outdoor air (as indicated by arrows labeledwith reference numeral 124) is circulated through outdoor heat exchanger30 using outdoor fan 32. More specifically, outdoor fan 32 is surroundedby fan shroud 36 that defines a shroud inlet 126 positioned closer tobulkhead 46 relative to a discharge 128 defined adjacent rear grill 22.In this manner, outdoor fan 32 urges a flow of outdoor air 124 inthrough rear grill 22 around lateral sides of air conditioner unit 10and fan shroud 36. The outdoor air is drawn toward shroud inlet 126 anddischarged through outdoor heat exchanger 30 and out rear grill 22.Notably, outdoor fan 32 tends to generate negative pressure withinoutdoor portion 14, particularly in regions closer to shroud inlet 126,bulkhead 46, or vent aperture 80. The negative pressure tends to developor increase as the outdoor air 124 approaches shroud inlet 126.

According to an exemplary embodiment of the present subject matter, fanduct 102 may define a geometry and be positioned such that inlet 106 ispositioned at a location where the negative pressure generated byoutdoor fan 32 does not significantly affect the ability of auxiliaryfan 120 to draw make-up air 122 into flow passage 104. In this manner,for example, fan duct 102 may extend towards rear grill 22 such thatinlet 106 is positioned proximate rear grill 22. According to anexemplary embodiment, inlet 106 may be directly coupled to or defined byrear grill 22. Notably, such positioning of inlet 106 allows auxiliaryfan 120 to draw in make-up air 122 without having to compete withoutdoor fan 32.

Referring now specifically to FIGS. 6 through 9, inlet 106 of fan duct102 may be positioned between a rear 130 of air conditioner unit 10 andshroud inlet 126 of fan shroud 36 along the transverse direction T.According still another embodiment, air conditioner unit 10 may definean outside depth 132 between bulkhead 46 and rear grill 22 along thetransverse direction T. In addition, the duct length 134 may be definedbetween inlet 106 and outlet 108 of fan duct 102 along the transversedirection. According to an exemplary embodiment, duct length 134 isgreater than or equal to one quarter of outside depth 132, or greaterthan one half of outside depth 132. Other suitable lengths of fan duct102 are possible and within scope of the present subject matter.

Referring now specifically to FIGS. 7, 9, and 10, fan duct 102 mayfurther be shaped to provide sufficient distance between inlet 106 andshroud inlet 126, e.g., to avoid the negative pressure generated byoutdoor fan 32 and to prevent the propagation of noise through fan duct102. In this regard, the inventors the present subject matter havedetermined that forming an asymmetric duct that breaks some or alldirect line of sight from inlet 106 to outlet 108 may reduce noisetransmitted to indoor portion 12. Therefore, according to theillustrated embodiment, fan duct 102 is asymmetric when viewed along ahorizontal plane (e.g., defined by lateral direction L and transversedirection T) such that inlet 106 and outlet 108 are offset along thetransverse direction T. In this regard, according to one exemplaryembodiment, there is limited line of sight from inlet 106 to outlet 108of fan duct 102. For example, as shown in FIG. 10, only a fraction ofvent aperture 80 may be seen through inlet 106 when looking along thetransverse direction T (such as less than 25 percent, 10 percent, oreven less than 5 percent of the total area of vent aperture 80).According to another embodiment, there is no direct line of sight frominlet 106 to outlet 108 along the transverse direction T.

Notably, fan duct 102 may be formed by injection molding, e.g., using asuitable plastic material, such as injection molding grade high impactpolystyrene (HIPS) or acrylonitrile butadiene styrene (ABS).Alternatively, according to the exemplary embodiment, fan duct 102 iscompression molded, e.g., using sheet molding compound (SMC) thermosetplastic. However, difficulties may arise in using such manufacturingtechniques due to the complex geometry of fan duct 102. For example,some mold tools may not be capable of forming an asymmetric fan duct inone piece without complex tooling, post processing, or othermanufacturing procedures. Therefore, according to an exemplaryembodiment of the present subject matter, fan duct 102 includes an upperportion 140 and a lower portion 142 that are separately formed, e.g.,via compression molding, and are subsequently joined to form fan duct102.

More specifically, referring to FIGS. 11 and 12, upper portion 140 maybe an upper half of fan duct 102 and lower portion 142 may be lower halfof fan duct 102. To facilitate the joining of upper portion 140 andlower portion 142, upper portion 140 may define an upper flange 144 andlower portion 142 may define a lower flange 146 that extend along alength of fan duct 102. Upper flange 144 and lower flange 146 may bejoined together in any suitable manner. For example, upper flange 144and lower flange 146 may be joined using one or more mechanicalfasteners, such as screws, bolts, rivets, etc. Alternatively, glue,welding, snap-fit mechanisms, interference-fit mechanisms, or anysuitable combination thereof may join upper flange 144 and lower flange146.

According to the illustrated embodiment, upper flange 144 and lowerflange 146 are joined using an adhesive. In this regard, upper flange144 may define an upper channel 148 and lower flange 146 may define alower channel 150 which are shaped for receiving an adhesive. Duringassembly, the upper channel 148 and the lower channel 150 are filledwith adhesive and upper flange 144 is clamped together with lower flange146 until the adhesive cures to form fan duct 102.

According to an exemplary embodiment, fan assembly 100 may furtherinclude an isolation member 160 that is positioned between auxiliary fan120 and fan duct 102. Isolation member 160 may be formed from anelastomeric or rubber material, such as silicone or a thermoplasticelastomer. In general, isolation member 160 is designed to absorbvibrations generated by auxiliary fan 120 during operation. In thismanner, isolation member 160 prevents these vibrations from propagatingthrough fan duct 102 and generating noise inside indoor portion 12.

Referring specifically to FIGS. 11 through 13, isolation member 160 ispositioned around auxiliary fan 120 and within fan duct 102. In thisregard, for example, isolation member 160 generally defines an innersurface 162 and an outer surface 164. Inner surface 162 is configuredfor engaging auxiliary fan 120 and outer surface 164 is configured forengaging fan duct 102. More specifically, to couple isolation member 160to fan duct 102, upper portion 140 of fan duct 102 may further define anupper bracket 166 and lower portion 142 of fan duct 102 may furtherdefine a lower bracket 168. When upper portion 140 and lower portion 142are joined to form fan duct 102, a bracket gap 169 (see FIG. 11) isdefined between upper bracket 166 and lower bracket 168.

Isolation member 160 further defines one or more isolation flanges 170which are sized for receipt in bracket gap 169 between upper bracket 166and lower bracket 168. In addition, screw holes 172 may be definedthrough upper bracket 166, lower bracket 168, and isolation flange 170for receiving a mechanical fastener. In this manner, isolation member160 may be secured within fan duct 102. Although upper portion 140 andlower portion 142 of fan duct 102 are illustrated herein as being joinedboth by an adhesive and a mechanical fastener, it should be appreciatedthat any suitable means for connecting the two may be used according toalternative embodiments. For example, upper bracket 166 and lowerbracket 168 could instead be extensions of flanges 144, 146 and could beassembled using an adhesive.

According to the illustrated embodiment, auxiliary fan 120 defines anaxial direction A, a radial direction R, and a circumferential directionC. In addition, auxiliary fan 120 defines a fan perimeter 180 which issubstantially circular and positioned between an upstream flange 182 anda downstream flange 184 which are separated along the axial direction A.According to the illustrated embodiment, isolation member 160 extendsall the way around the entire fan perimeter 180. More specifically,isolation member 160 is substantially rectangular and includes foursides. Isolation member 160 further defines a plurality of complementarymating features 190 that extend from inner surface 162 toward auxiliaryfan 120 for securing auxiliary fan 120. For example, the complementarymating features 190 may be curved or arcuate members that engage fanperimeter 180 to secure auxiliary fan 120 in place. As used herein,terms of approximation, such as “approximately,” “substantially,” or“about,” refer to being within a ten percent margin of error.

Notably, complementary mating features 190 may also be sized forsecuring the axial position of his auxiliary fan 120 within fan duct102. In this regard, for example, auxiliary fan 120 defines a flange gap192 between upstream flange 182 and downstream flange 184 along theaxial direction A. Complementary mating features 190 are positionedwithin flange gap 192 to prevent auxiliary fan 120 from moving axially.More specifically, for example, flange gap 192 may define a gap width194 along the axial direction A that is substantially the same as thefeature width 196 defined by the complementary mating feature 190 alongthe axial direction A. Although four complementary mating features 190are illustrated as positioned on each side of a rectangular isolationmember 160, it should be appreciated that any suitable number, size, andposition of mating features may be used according to alternativeembodiments.

Although auxiliary fan 120 is illustrated above as being directlymounted within fan duct 102, it should be appreciated that according toalternative embodiments, fan assembly 100 could instead include a fanmounting structure that is separately assembled and attached to fan duct102. In this manner, according to alternative embodiments, auxiliary fan120 may be inserted into isolation member 160 and then installed ontothe fan mounting structure. The fan mounting structure could then beseparately installed onto a fan duct before mounting to bulkhead 46.Other configurations and constructions are possible and within the scopeof the present subject matter.

In sum, isolation member 160 and the fan installation method andconfiguration described above can isolate auxiliary fan 120 from fanduct 102 and reduce noise generated by auxiliary fan 120 while providingmake-up air. In this regard, by positioning an elastomeric or rubbermaterial between auxiliary fan 120 and fan duct 102 (or any othersuitable fan mounting structure), vibrations transferred to fan duct 102may be reduced significantly. Isolation member 160 may be formed in aband around fan perimeter 180 of auxiliary fan 120 and may includevarious protrusions or other features, e.g., mating features 190, forlocating and securing auxiliary fan 120 in position within fan duct 102.In addition, isolation member 160 may define one or more isolationflanges 170 that may be secured to fan duct 102 during assembly, therebyfixing isolation member 160 and auxiliary fan 120 relative to fan duct102.

Isolation member 160 thus provides a unique means of locating andretaining an auxiliary fan within a fan duct while isolating or dampingvibrations generated during fan operation. Isolating the fan as a noisesource will reduce or eliminate noise which may be a nuisance tooccupants of the conditioned room and otherwise result in a moredesirable consumer experience. Other configurations of fan duct 102 andisolation member 160, as well as associated benefits and advantages ofsuch constructions, will be apparent to those having skill in the art.

Referring now to FIG. 14, auxiliary fan 120 will be described accordingto an exemplary embodiment of the present subject matter. It should beappreciated that the auxiliary fan 120 illustrated in FIG. 14 anddescribed herein is only one exemplary configuration of auxiliary fan120. As illustrated, auxiliary fan 120 defines an axial direction A, aradial direction R, and a circumferential direction C. Auxiliary fan 120includes a plurality of fan blades 210 that generally extend between aroot 212 and a tip 214. According to the illustrated embodiment, fanblades 210 includes seven blades positioned equidistantly about thecircumferential direction C. Fan blades 210 are sized, spaced, anddefine a twist or camber that allow fan blades 210 to block asubstantial portion of noise trying to pass through auxiliary fan 120,e.g., when auxiliary fan 120 is off. However, it should be appreciatedthat according to alternative embodiments, any suitable number, size,and geometry of fan blades 210 may be used.

In addition, auxiliary fan 120 includes a stabilizer ring 216 thatextends about the circumferential direction C to couple fan blades 210.Stabilizer ring 216 is a generally rigid circular member configured toprovide rigidity between fan blades 210 to prevent “growl” or “flutter”of fan blades 210, particularly during transient operation when thespeed of auxiliary fan 120 changing. Stabilizer ring 216 is preferablypositioned proximate tips 214 of fan blades 210, where blade distortionor flutter might be most extreme.

More specifically, according to the illustrated embodiment, fan bladesdefine a root diameter 220 and a tip diameter 222. In addition,stabilizer ring 216 defines a ring diameter 224. According to anexemplary embodiment, ring diameter 224 is between about 50% greaterthan a root diameter 220 and 10% less than tip diameter 222. Accordingto still another embodiment, ring diameter 224 is substantially the sameas tip diameter 222. In addition, stabilizer ring 216 may be positionedonly at a forward most end of blades 210 along the axial direction A,the aft most end of blades 210 along the axial direction A, or at both.Moreover, according to the illustrated embodiment, blades 210 may definea blade depth along the axial direction A and the stabilizer ring 216may extend substantially along the entire blade depth of fan blades 210.

Referring now to FIGS. 15 through 17, fan assembly 100 further includesan electronics assembly 240 which is generally configured for housingelectronic components used for driving auxiliary fan 120, vent door 82,or any other components of air conditioner unit 10. In general,electronics assembly 240 includes an electronics enclosure 242 that ismounted to fan duct 102 and generally defines an electronics compartment244 that is used for housing electronic components. For example,according to exemplary embodiments, controller 64 (or any other suitablecontrol electronics) may be housed within electronics enclosure 242,such that auxiliary fan 120 may be controlled by controller 64. Inaddition, an inverter or other power electronics may be stored withinelectronics enclosure 242 to convert or rectify an input power to apulse with modulated (PWM) signal as needed for driving auxiliary fan120.

More specifically, electronics enclosure 242 may be a five sided boxdefining an opening 246 through which electronic components may beinserted into electronics compartment 244. Electronics assembly 240 mayfurther include a top plate 248 that is attachable over opening 246 ofelectronics enclosure 242 to substantially enclose electronicscompartment 244. Inverter or other power electronics may be attacheddirectly to top plate 248 so that they are contained within electronicscompartment 244.

In order to seal electronics enclosure 242 from the outside elements andsafely contain all electronic components within electronics compartment244, electronics assembly 240 may further include a seal 250 positionedbetween electronics enclosure 242 and top plate 248. For example, seal250 may be an O-ring formed from an elastomeric or rubber material suchthat it is resilient and is compressed when top plate 248 is attached toelectronics enclosure 242. In this regard, for example, top plate 248may be mounted to electronics enclosure 242 using one or more mechanicalfasteners 252. In addition, it should be appreciated that top plate 248defines a footprint that is larger than an outer flange 260 ofelectronics enclosure 242. In this manner, positioning top plate 248over opening 246 substantially seals opening 246 and forms a single,enclosed electronics compartment 244.

In addition, as best illustrated in FIG. 16, electronics enclosure 242,or more specifically outer flange 260, defines a perimeter groove 262that extends around a perimeter of electronics enclosure 242 and isconfigured for receiving seal 250. Moreover, electronics enclosure 242may define a wire recess 264, e.g., through which wires are routed via agrommet to auxiliary fan 120. Wire recess 264 may also define a recessgroove 266 for partially receiving seal 250. In this manner, seal 250has a single, continuous grooved pathway defined around all matingsurfaces between electronics enclosure 242, top plate 248, and grommet(not shown).

According to an exemplary embodiment, top plate 248 is formed to be athermally conductive member for allowing heat to escape electronicscompartment 244. In this regard, for example, top plate 248 may defineor include a heat sink 270. In addition, top plate 248 may beconstructed of a thermally conductive material, such as aluminum. Bycontrast, electronics enclosure 242 may be formed from a thermosetplastic or any other suitable material. According still anotherembodiment, electronics enclosure 242 may also be formed from athermally conductive material, such as metal or aluminum.

As best illustrated in FIGS. 11, 12, 16, and 17, fan assembly 100 mayfurther define features for simplifying the assembly of electronicsenclosure 242 to fan duct 102. In this regard, fan duct 102 may defineone or more mounting pads 280 that protrude from fan duct 102 andelectronics enclosure 242 may define one or more mounting recess 282. Asused herein, “mounting pads” are features that are configured forreceipt within “mounting recesses” to align and mount electronicsenclosure 242 to fan duct 102. It should be appreciated that althoughfan duct 102 is illustrated as defining mounting pads 280 andelectronics enclosure 242 is illustrated as defining recesses 282, thetwo features could be swapped. In this regard, electronics enclosure 242could instead define mounting pads 280 and fan duct 102 could insteaddefine recesses 282. Other configurations are possible and within scopeof the present subject matter.

Moreover, according to an exemplary embodiment, mounting pads 280 andmounting recesses 282 are configured for receiving an adhesive forjoining electronics enclosure 242 and fan duct 102. These features mayfurther define profiles simplify the alignment assembly of electronicsenclosure 242 and fan duct 102. For example, according to theillustrated embodiment upper portion 140 of fan duct 102 defines twoL-shaped mounting pads 280 that are configured for engaging a bottom 284and a back 286 of electronics enclosure 242. In this manner, assembly offan assembly 100 is simplified because a technician can easily alignelectronics enclosure 242 onto fan duct 102 by sliding it along theL-shaped mounting pads 280 until they contact back 286. In addition,upper portion 140 also defines a lateral mounting pad 280 that isconfigured to engage outer flange 260 of electronics enclosure 242. Insum, these features simplify the alignment and positioning of fan duct102 and electronics enclosure 242 as well as the assembly andinstallation of fan assembly 100.

Thus, electronics assembly 240 and electronics enclosure 242 describedherein are capable of housing electronics components safely and securelywithin an outdoor environment. Top plate 248 of electronics enclosure242 includes heat sink 270 having a larger footprint than electronicsenclosure 242 to prevent fluid entry through opening 246. In addition,extruded O-ring seal 250 is positioned within a groove 262 formed withinouter flange 260 of electronics enclosure 242 such that securing topplate 248 to electronics enclosure 242 compresses the O-ring and sealselectronics compartment 244.

Moreover, fan duct 102 and electronics enclosure 242 are permanentlyadhered together using an adhesive. More specifically, mounting pads 280and complementary recesses 282 may be defined on fan duct 102 andelectronics enclosure 242. These mounting pads 280 and recesses 282interact or engage each other to provide adhesive locations forpermanently attaching fan duct 102 to electronics enclosure 242. Fanduct 102 and electronics enclosure 242 may be assembled prior to finalinstallation into air conditioner unit 10, thereby making theintegration of the make-up air features less labor intensive and easierto service.

As described above, fan assembly 100 includes fan duct 102 which ismolded as two pieces that are joined together using an adhesive, therebysimplifying tooling and ensuring easy assembly. In addition, each piecemay be compression molded from a thermoset material or another flameresistant material, allowing for simple mold tooling and part formation.The thermoset materials and adhesive used to join the two pieces exhibitinherent flame retardant properties, which is particularly importantbecause fan duct 102 is positioned in a region where flame propagationis a concern.

Moreover, forming fan duct 102 as described herein allows fan duct 102to have unique shapes and geometry for reducing the propagation of noisethrough fan duct 102 and vent aperture 80. In this regard, for example,fan duct 102 has an asymmetrical or offset arrangement along thetransverse direction T, e.g., such that there is no direct line of sightbetween inlet 106 and outlet 108 along the transverse direction T.Moreover, fan duct 102 may protrude rearward, e.g., past outdoor fanshroud 36 and proximate rear grill 22, such that inlet 106 is positionedin a region where effects of the negative pressures developed by outdoorfan 32 may be reduced or avoided.

In addition, a unique construction of auxiliary fan 120 is providedwhich may reduce noise generated by auxiliary fan 120. For example,conventional axial fans generated blade “growl” or fluttering,particularly when the fan is shut off or changes speeds. This noise mayhave a tendency to propagate through fan duct 102, producingunacceptable noise within the room or indoor portion 12. However,auxiliary fan 120 described above may include more blades 210, astabilizer ring 216, and blade geometries that results in asignificantly quieter operation. For example, the rate of change ofrotational speed of auxiliary fan 120 is lower due to higher inertia,the increased number of blades and their geometry deflect outside toinside noise transmission, etc. The fan construction, duct construction,and other noise isolating features provide an acoustic advantage to airconditioner unit 10 described herein.

In this manner, air conditioner unit 10 includes fan assembly 100 whichhas fan duct 102 and auxiliary fan 120 that provide the appropriateamount of make-up air to meet government regulations and building codes,keeps the noise created by fan assembly 100 to a minimum, and maintainsguest comfort and satisfaction at a maximum. In addition, themanufacturing, assembly, and installation of fan assembly 100 aresimplified, tooling costs are reduced, and the reliability andperformance of air conditioner unit 10 is improved. Other advantages andbenefits will be apparent to those having skill in the art.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they include structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

What is claimed is:
 1. A packaged terminal air conditioner unit defininga vertical, a lateral, and a transverse direction, the packaged terminalair conditioner unit comprising: a bulkhead defining an indoor portionand an outdoor portion separated along the transverse direction; a ventaperture defined in the bulkhead; and a fan duct defining a flow passagehaving an inlet and an outlet, the outlet of the fan duct being attachedto the bulkhead to fluidly couple the flow passage to the vent aperture,and the inlet extending away from the bulkhead toward a rear of thepackaged terminal air conditioner unit.
 2. The packaged terminal airconditioner unit of claim 1, wherein the inlet is positioned proximate arear grill of the packaged terminal air conditioner unit.
 3. Thepackaged terminal air conditioner unit of claim 2, wherein an outsidedepth is defined between the bulkhead and the rear grill along thetransverse direction, and a duct length is defined between the inlet andthe outlet of the fan duct along the transverse direction, the ductlength being greater than or equal to half of the outside depth.
 4. Thepackaged terminal air conditioner unit of claim 1, wherein the inlet ofthe fan duct is positioned between the rear of the packaged terminal airconditioner unit and a shroud inlet of a fan shroud along the transversedirection.
 5. The packaged terminal air conditioner unit of claim 1,wherein the inlet and the outlet of the fan duct are offset along thetransverse direction.
 6. The packaged terminal air conditioner unit ofclaim 1, wherein there is no direct line of sight of the outlet of thefan duct when looking through the inlet along the transverse direction.7. The packaged terminal air conditioner unit of claim 1, wherein thefan duct comprises an upper portion and a lower portion joined using anadhesive.
 8. The packaged terminal air conditioner unit of claim 7,wherein the upper portion and the lower portion are separately formed bycompression molding.
 9. The packaged terminal air conditioner unit ofclaim 7, wherein the upper portion and the lower portion are formed fromsheet molding compound (SMC) thermoset plastic.
 10. The packagedterminal air conditioner unit of claim 7, wherein the lower portiondefines a lower flange having a lower channel and the upper portiondefines an upper flange having an upper channel, the lower channel andthe upper channel being filled with adhesive and the lower flange andthe upper flange being joined to form the fan duct.
 11. The packagedterminal air conditioner unit of claim 1, comprising: an auxiliary fanmounted to the fan duct and being configured for urging a flow ofmake-up air from the outdoor portion through the flow passage and thevent aperture to the indoor portion.
 12. The packaged terminal airconditioner unit of claim 11, wherein the auxiliary fan defines anaxial, a radial, and a circumferential direction, the auxiliary fancomprising: a plurality of fan blades, each fan blade extending betweena root and a tip; and a stabilizer ring extending about thecircumferential direction between the plurality of fan blades.
 13. Thepackaged terminal air condition unit of claim 12, wherein the pluralityof fan blades define a root diameter and a tip diameter, and wherein thestabilizer ring defines a ring diameter, the ring diameter being betweenabout 50 percent greater than the root diameter and 10 percent less thanthe tip diameter.
 14. The packaged terminal air condition unit of claim12, wherein the plurality of fan blades comprise seven fan blades andwherein the stabilizer ring is positioned proximate a tip of the sevenfan blades.
 15. The packaged terminal air conditioner unit of claim 12,wherein the stabilizer ring is attached at a forward end or an aft endof the plurality of fan blades.
 16. The packaged terminal airconditioner unit of claim 12, wherein the plurality of fan blades definea blade depth along the axial direction, the stabilizer ring extendingalong substantially the entire blade depth of the fan blades.
 17. A fanassembly for a packaged terminal air conditioner unit, the packagedterminal air conditioner unit defining a vertical, a lateral, and atransverse direction, the packaged terminal air conditioner unitcomprising a bulkhead defining a vent aperture, the fan assemblycomprising: a fan duct defining a flow passage having an inlet and anoutlet, the outlet of the fan duct being attached to the bulkhead tofluidly couple the flow passage to the vent aperture, and the inletextending away from the bulkhead toward a rear of the packaged terminalair conditioner unit; and an auxiliary fan mounted to the fan duct andbeing configured for urging a flow of make-up air through the ventaperture, the auxiliary fan defining an axial, a radial, and acircumferential direction and comprising: a plurality of fan blades,each fan blade extending between a root and a tip; and a stabilizer ringextending about the circumferential direction between the plurality offan blades.
 18. The fan assembly of claim 17, wherein the inlet of thefan duct is positioned between the rear of the packaged terminal airconditioner unit and a shroud inlet of a fan shroud along the transversedirection.
 19. The fan assembly of claim 17, wherein the inlet and theoutlet of the fan duct are offset along the transverse direction. 20.The fan assembly of claim 17, wherein the plurality of fan bladescomprise seven fan blades and wherein the stabilizer ring is positionedproximate a tip of the seven fan blades.